US2957282A

US2957282A - Reciprocating mounting means for mounting thereon a sanding or like tool

Info

Publication number: US2957282A
Application number: US574913A
Authority: US
Inventors: Bernard A Swanson
Original assignee: Individual
Current assignee: Individual
Priority date: 1956-03-29
Filing date: 1956-03-29
Publication date: 1960-10-25
Anticipated expiration: 1977-10-25

Description

Oct. 25, 1960 B. A. SWANSON 2,95

RECIPROCATING MOUNTING MEANS FOR MOUNTING THEREON A szmnmc; OR LIKE TOOL Filed March 29, 1956 3 Sheets-Sheet 1 JNVENTOR. flex-17am If 5wans on 177 TORNEY Oct. 25, 1960 B. A. SWANSON ,9

RECIPROCATING MOUNTING MEANS FOR MOUNTING THEREON A SANDING OR LIKE TOOL Filed March 29, 1956 3 Sheets-Sheet 2 -J h 158 i Q 5 3 n5- (5 5/ 57 5/ 57a r 5s IN VEN TOR.

Bernard 1?. Swanson ATTORNEY Oct. 25, 1960 B. A. SWANSON 2,957,232

RECIPROCATING MOUNTING MEANS FOR MOUNTING THEREON A SANDING 0R LIKE TOOL IN V EN TOR.

Bernard l2 Jn'msoh ATTORNEY United States Patent O'ice RECIPROCATING MOUNTING IVIEANS FOR MOUNTING THEREON A SANDING OR LIKE TOOL Bernard A. Swanson, Sacramento, Calif. (Bellevue, Wash.)

Filed Mar. 29, 1956, Ser. No. 574,913

7 Claims. (Cl. 51-170 My invention relates to a reciprocating mounting means for mounting thereon a sanding or like tool.

More particularly, my invention relates to a reciprocating mounting means characterized by the facility and controlability with which it may be employed due to its freedom from transmitting objectionable vibrating impulses to the hand of the operator when there is mounted thereon a sanding, polishing, scraping, rubbing, massaging, or like device. 7

Present devices commonly employed for the purposes indicated present a serious objection as to the small power directly available to perform work.

There is also a great objection to present devices, for accomplishing these various purposes, occasioned by the severity and magnitude of the vibratory impulses transmitted to the hand of the operator as commonly in use.

Another objection to present devices of the types indicated is their weight and bulkiness which, combined with the generation of vibrations in the hand of the operator, cause rapid operator fatigue.

Another objection is the relatively large compressed air supply requirements of such prior devices. In short, said devices customarily and inefliciently employ and require a large volume of fluid pressure to operate the .same. Such devices, complicated in their structure, are very costly in manufacture, and likewise are very costly to operate.

A primary object of my invention is to overcome all of the above objections and difliculties.

Particularly it is a primary and fundamental object of my invention to provide the mechanism set forth characterized by having a motor of the fluid pressure reciprocatory type which develops effective high speed reciprocatory movement, with far greater reciprocation speeds than like devices commonly employed for accomplishing like purposes.

Further, it is a primary object of my invention to provide such a device which economically develops exceedingly great working power in proportion to the volume of fluid pressure employed.

A further primary and fundamental object of my invention is to provide a mechanism characterized by a structure and mode of operation which does not permit the stalling of the motor regardless of the degree of pressure with which the device is held against the work. Such pressure may be of such magnitude that even stalling of the vibratory plate or base will not stall or injure the motor and will not injure or fatigue the operator, nor will such operator lose control of the mechanism regardless of the size of the unit. Normally, compressed air constitutes a dangerous source of power should the device become stalled, i.e. it whips the device about so that the operator normally loses control and even may become seriously injured.

A further primary object of my invention is to provide a device of the class described which does not depend for its effectiveness upon the vibratory force reacting upon the hand of the operator.

Patented Oct. 25, 19.60

Also, it is a primary object of my invention to cushion by fluid pressure the reciprocating piston so that the piston does not develop its vibratory force by direct contact with the end walls of the motor cylinder.

Also, it is a primary object of my invention to provide a mechanism characterized by having the motor mounted upon a vibratory tool mounting plate or base vibrationally independent of the handle housing by which the device is manipulated by the operator.

. An object of the invention is to provide a machine which will efiectively sand or polish various objects and surfaces, which machine may be portable if desired.

Another object of the invention is to provide a sanding and polishing machine which embodies a reciprocating sanding or polishing block which is actuated by an air engine of the reciprocating type, whereby the tool can be readily used for sanding woodwork, scraping and polishing surfaces, and sanding out rust spots, or for rubbing and massaging purposes, as desired.

A further object is to provide a pneumatic sanding and polishing machine which is extremely simple and inexpensive to manufacture and to operate, and which may be designed to be portable if desired.

Further and more specific objects of the present invention involve presentation of various forms thereof, including one form of the invention wherein the mechanism comprises a motor and base plate assembly, the motor including a cylinder fixedly secured to said base plate, with handle means in spaced relation to said base plate and flexible means exhibiting three-dimensional resiliency connecting said handle means and said assembly at the base plate of the latter, and presentation of another form of the invention wherein such flexible means connects said handle means and the cylinder of said assembly.

Other objects and advantages will be apparent to those skilled in the art from the following description of various typical embodiments of the invention, set forth by way of illustration and not limitation.

For purposes of clarity and readiness of understanding, and not by way of limitation as to field of application, my invention is set forth below as applied to sanding, scraping, rubbing, polishing, and massaging devices.

The foregoing general objects of my invention, together with others inherent in the same, are attained by the mechanism illustrated in the following drawings, throughout which like reference numerals indicate like parts: 7

Figure l is a view in longitudinal medial cross-section, with various parts in side elevation, of a tool embodying my invention, showing the reciprocatory piston 'at one stage of travel;

Fig. 2 is a view partly in side elevation and partly in longitudinal medial cross-section of the same, showing the reciprocatory piston at another stage of travel;

Fig. 3 is a view in cross-section substantially on broken line 3-3 of Figure 1;

Fig. 4 is a detached view in side elevation of a motor and base plate assembly according to the present invention;

Fig. 5 is a view in transverse vertical cross-section similar to Figure 1, but showing a modified form of tool according to the present invention which is provided with scraper blades, and is well adapted for use as a paint scraper;

Fig. 6 is a fragmentary view partly in plan and partly in horizontal cross-section showing an elastic and resilient connecting means, of modified form as used in the machine shown in Fig. 5, for providing vibrational separation between a handle housing and a reciprocatory tool carrying assembly supporting and guided by said handle housing;

Fig. 8 is a fragmentary. cross-sectional partial view of the other end part of the block or base plate and scraper blade assembly shown in Fig. 7, showing the scraper blades inclined in an opposite direction;

Fig. 9 is a detached fragmentary perspective partial viewfshowing a scraper blade and scraper blade frame means; a a

Fig. 10 is a detached fragmentary perspective partial view, showing scraper blade frame means and devices for holding scraper blades while they are being sharpened;

Fig. '11 is a view in cross-section of a modified form of the scraper blade showing the bottom portion hollow Fig. 12 is a view of a modified form of the blade cutting mechanisnyeach of which comprises a group or plurality of blades contacting each other substantially throughout their width;

Fig. 13 is a fragmentary perspective partial view of a modified form of the center or intermediate blade of the form of the blade cutting mechanism shown inFig. 12;

Fig. 14' is a view in longitudinal medial cross-section,

'with various parts shown in side elevation, of a modified form of mechanism embodying by invention, wherein the resilient connecting means between the motor and base plate assembly and handle housing comprises a rectangu-v lar flexible casing connecting to said motor and base plate assembly at the lateral edges of the cylinder thereof;.and Fig. 15 is a view in transverse vertical cross-section of the modified form of the invention illustrated in Fig. 14, taken substantially along line 1515 thereof.

Referring in detail to the drawings, Figs. 1 to 4, in-

clusive, the said machine of my invention comprises a housing 10 which is adapted to be conveniently gripped. in the users hand, and the housing 10 is provided with a fluid pressure passageway 11. A fitting 12 is arranged on the housing 10 in registry with the passageway 11,

whereby a suitable hose 13 can be connected thereto for carrying fluid, such as compressed air, from a source of supply, not shown. A spring-pressed control valve 14' is arranged in the passageway 11 for normally preventing flowof fluid therethrough, and a manually-operable actu ating member 15 is connected to the valve by a stem 16, the actuating member 15 being pivoted to the housing and forth. The said base plate 21 is provided with a channelway 22 which is connected to the passageway 11in the housing 10 by means of a flexible hose 23. Therbase plate 21 is dependingly'supported below the housing 10 by means of a flexible or rubber strip 24. The upper end of the strip 24 is secured to the housing 10 by metal strap 25, there'being screws 26 projecting through the strap 25, the rubber strip 24, and into the housing 10. A plurality of L-shaped brackets 27 are secured to the base plate 21 by securing elements, such as bolts 28, and the lower por-' tions of the rubber or flexible strap 24 is secured to the brackets .27 by means of a retaining band 29 anda plu rality of screws 30.

Positioned between the plate 19 and the base 21 is an engine or motor 31 of the fluid pressure operated reciprocatory type. The engine comprises a cylinder 32 which maybe connected to the base or plate 21 by a threaded brushing or nipple 33 whereby movement of the cylinder 2,957,:asa

32 causes movement of said base plate 21. Headed bolts 34 further secure the base 21 to the cylinder 32. Reciprocatingly arranged in the cylinder 32 is a piston 35 which receives compressed air from the port or annular recess 36 in the cylinder 32. The piston 35 is provided with a pair of spaced

passageways

37 and 38 which alternately discharge air against opposite ends of thecylinder 32 and thereby cause independent movement of both the cylinder 32 and piston 35 so that the cylinder 32 is also free to reciprocate. The piston 35 has a hill-lug 35a and 35b at each end and a third hill-lug 35c intermediate said ends. Said third hill-lug 350 has lateral valleys 35d and 35e on each side thereof and also a fluid pressure inlet starting groove 35 which groove has'a seepage starting conduit 35g connecting said groove 35f with one of said connecting conduits or' passageways such as 38. The air exhausts through the aperture or exhaust ports 39 in the cylinder 32, then through the openings 20 in the plate 19, and finally out through the bore 40 in the housing. v

V A strip of abrasive 41, such as sandpaper, is carried by a snap-on locking or mounting plate 43, anda rubber pad 42 is interposed between the abrasive sheet or strip 41 and the snap-on plate 43 whichhas resilient rolled ends 44 adapted to snap into notches 45 of base plate 21.

In use, compressed air or other fluid is conveyed through the housing 10 in ,controlled amounts, andthe fluid causes the piston 35 to reciprocate in cylinder 32 and thereby likewise cause Said cylinder 32 to reciprocate and thereby cause the base 21 carrying the abrasive sheet 41 to move back and forth.

The fluid, pressure operated mo'tor herein set forth and its advantageous characteristics are more fully described and claimed in 'my co-pending application Ser. No. 390,617, filed November 6, 1953, now US. Patent No. 2,821,962, entitled Engines, which application is in turn a continuation-in-part of my application Ser. No. 97,661, filed June 7, 1949, and entitled Fluid Pressure Operated Reciprocatory Vibratory Sheet Metal Cutting Shears, and to which reference should be made for a more comprehensive consideration of the details and advantageous features thereof.

The piston 35 is cushioned in its're ciprocatory movement by the inrushing air. The sudden stoppinglof the piston 35 imparts its momentum to the cylinder 32. The piston 35 and cylinder 32 both reciprocate as just set'forth so that the operator will experience a minimum of recoil, while maximum power will be delivered by the machine. The machine thus sands and polishes by reciprocating movement of the abrasive sheet 41, in contrast to the conventional circulatory movement of abrasive sheets.

The scraper shown in Figs. 5 to 10 includes parts as follows, which are similarv to'the correspondingly numbered parts in Figs. 1 to 4: A housing 10, inlet and control means for fluid under pressure 11 to 17, inclusive, and 23, and

motor parts

31, 32, and'35 to 39, inclusive. In the interest ofbrevity, the description of these parts is not herein repeated.

A reciprocable block or base plate 21a, shown in Figs. 5,7, and 8, is similar to the base plate 21 shown in Figs. 1 to 4, and is provided with a passageway 22a similar to the passageway 22, and is secured to the motor 31 by screws 58 which correspond to the screws 34' of Figs. 1 and 2.

The flexible and elastic mounting means shown in Figs; 5 and 6 for connecting the handle housing 10 with the reciprocable block or base plate 21a is in the formof a box-shaped connector member of rubber, polyethylene, or like elastic material exhibiting three-dimensionalresiliency. The resilient mounting means as shown in Figs. 5 and 6 is' the preferred form of a rectangular flexible housing, i.e., box-shaped housing. Such resilent mounting means comprises a plane flat bottom 50, two end walls 51 and two transversely corrugated side walls 52. An inwardly extending flange 53, integral with both the end walls 51 and side walls 52, extends around the top of the flexible mounting means. The flange 53 seats within an external groove 54 which extends around the bottom portion of the housing 10. A metal clamp band 55 ex tends around the upper marginal portion of the end walls 51 and side walls 52 and secures the flexible mounting means to the housing 10. Preferably the clamp band 55 has two out-turned, perforated end portions 55a which are connected by a bolt 56 so that the band 55 may be tightened like a hose clamp on the flanged part 53 of the flexible mounting means or connector. One of the outturned end portions 55a and the bolt 56 are shown at the right in Fig. 5.

The elastic end walls 51 are of fairly thick rubber, for example, and will transmit a substantial amount of downward pressure from the housing against the motor and base plate assembly and the scraperparts carried thereby, while at the same time said end walls 51 will bend or flex freely, notwithstanding said downward pressure, to permit reciprocation of the scraper parts relative to the handle housing 10. The corrugated side walls 52 are thinner than the end walls 51 and the corrugations extend between the bottom 50 and the top flanges 53 of the walls 52, and these corrugated walls 52 will flex and bend more easily in directions longitudinally of the tool than a non-corrugated piece of like elastic material of the same dimensions, as will be apparent.

The bottom 50 of the flexible mounting means or elastic connecting member rests on the reciprocable base plate 21a. A metal plate 57, which preferably has upwardly curved edges 57a, is positioned within the rectangular or box-shaped flexible housing or elastic connector member and rests on the bottom 50 thereof. The motor 31 rests on the plate 57 and said motor and the plate 57 and bottom member 50 and reciprocable base plate 21a are all rigidly connected together by the screws 58. A suitable fitting 59, similar to fitting 33 of Figs. 1 and 2, communicatively connects the flexible conduit member 23 with the passageway 22a in the base plate 21a.

The ends of the base plate 21a are provided with grooves 60, shown in Fig. 8, to releasably receive the curved upper edge portions 61 of resilient end walls 62 of a blade carrying frame of rectangular shape. The blade carrying frame is thus quickly and easily attachable and detachable with respect to the base plate 21a by snapping the curved portions 61 thereof into and out of the notches 60 in the ends of said base plate 21a. Each side of the blade carrying frame is shaped somewhat like a letter J in cross section (see Figs. 9 and 10) and comprises an outer flange 63, a bottom part 64, and an inner notched flange 65 which is provided with notches 66. The resilient end walls 62 are fixedly secured to the

sides

63, 64, and 65 of the blade carrying frame at the corners.

Preferably the two opposed edges or sides of each notch 66 are closest together in a plane coincident with the top surface of the bottom part 64, and'these opposed notch sides diverge from each other vertically considered from this plane so that scraper blades 67 will be supported for pivotal movement in this plane of the top surface of the bottom 64, as hereinafter described.

Each scraperblade 67 is a plane flat piece of steel or like metal with a notch 68 of inverted L-shape adjacent each end thereof, said notches 68 leaving blade supporting end parts 69 of narrower width than the blades on the ends of the blades. The blades supporting parts 69 are adapted to rest on the bottom 64 of the blade carrying frame and the adjacent portions of the blades are positioned in the notches 66.

The notches 66 hold the blades firmly and at the same time the divergence of these notches allows said blades to rock or pivot between the inclined positions as shown respectively in Figs. 7 and 8. This applies the blade corners along the bottom or outer edges of the blades to the work at an angle best calculated for efiicient scraping.

A rectangular blade retaining frame 70 is positioned,

6 within the blade carrying frame in close proximity to the upper edges of the blades 67. The ends of this frame 70 are releasably but firmly received within depressions 71 in the resilient end parts 62 of the blade carrying frame. The thrust of the blades 67 is exerted against the frame 70 when the scraper is applied to an object to be scraped and the frame 70 prevents the blades 67 from falling out of the blade carrying frame when said blade carrying frame is detached from the reciprocable base plate 21a. The blade retaining frame 70 can be snapped into the notches 71 and is readily removable therefrom.

In the form of this invention shown in Fig. 5, fluid under pressure first exhausts through the ports 39 into the housing 10 and thence passes through perforations 72 in

parts

57, 50 and 21a and discharges or blows out between the blades 67. The exhaust fluid is thus used to dislodge scrapings from between the blades 67 and keep the scraper clean while it is in use, thereby greatly increasing the efiiciency of the tool. The bottom or outer portions may be hollow ground, if desired, thereby increasing the cutting or scraping action of the corners or edges.

In the operation of the scraper shown in Figs. 5 to 10, inclusive, the motor 31 provides rapid reciprocation of the base plate 21a and scraper parts carried thereby as hereinbefore explained in connection with Figs. 1 to 4.

Fig. 11 shows a blade 77 of modified form having a hollow ground work engaging edge 78 which may be advantageously used in some types of work.

Fig. 12 lllustrates a form of the invention in which each blade unit or blade cutting mechanism is made up of a group or plurality of separate blades 79 in juxtaposed or side-by-side contacting relation. In this form of the invention in which each blade unit is made up of a plurality of separate blades, each blade unit presents or applies a plurality of scraping edges to the work. The blade bottom or outer portions may be flat or hollow ground as desired;

Fig. 13 shows a blade 80 with a notched or serrated or saw-toothed work engaging edge 81 and which is preferably used between two of the blades 79 shown in Fig. 12. This form of intermediate blade functions to cut fast and break up a heavy coating of paint, or to quickly smooth down a rough surface for finishing.

If the corners of the scraping edges of the blades of the form shown in Fig. 5 become dull or rounded, they may be quickly and easily restored to a sharp condition by first applying to the scraper suitable means, as shown in Fig. 10, which Will prevent pivotal movement of the blades and will rigidly hold the blades perpendicular to the base plate 21a, and then placing the blades on a plane but rough abrasive surface and reciprocating the blades by supplying energy to the motor 31. One flat abrasive surface which could be used for sharpening would be sand or emery cloth or a paper supported on a flat plate. One device which may be used to rigidly secure the blades 67 in planes perpendicular to the plane of the reciprocable base plate 21a is shown in Fig. 10. This device comprises a bar or plate 73 having notches 74 adapted to fit over the blades 67 and hold these blades rigid and parallel and perpendicular to the base plate 21a. Devices are provided for rigidly securing the notched bar 73 to the bottom part 64 of one side of the blade carrying frame. These devices may be cap screws 75 extending through holes or slots 76 in the bar 73 and threaded into the frame part 64. Either one or two of the bars 73 may be used on a scraper, as

desired, and these bars may either be detached when not in use or, in some instances, may be retracted clear of the blades 67 and left attached to the scraper.

Turning to a consideration of a further modified form of the present invention as illustrated in longitudinal and transverse cross-sectional views in Figs. 14 and 15, respectively, such further form of the invention typifies and alternative manner of vibrationally isolating the motor and base plate assembly of the mechanism fi'om More specifically, the modified form of theinvention illustrated in Figs. 14 and l is shown with the mechanism at rest, i.e., with its plate assemblyin a central position with respect to the vibration cycle. As illustrated, the mechanism comprises a housing 100 provided with a. fluid pressure passageway 101. A fitting B12 is threaded- ;ly retained in housing 106 in registry 'with said passageway 101', and a fluid pressure delivery line such as a hose, 'a segment of whichis shown at 103, delivers fluid under pressure to said passageway 101 from a suitable source of ."supply, not shown. A ball control valve 104, spring pressed by spring 104a, is arranged in passageway 101 for regulating flow of fluid therethrough, and'a manually operable actuating member 105 is mechanically engaged with ball valve 194 by a stem 106, said actuating member 165 being pivoted to. housing 100 by pin 107.

Fibrous mass 1&3, such as asbestos, brass Wool or other non-corroding air-entraining material having sounddeadening properties is contained in the interior of housing 109 and maintained in position therein by means of a;removable plate 199, which is in turn provided with a plurality of spaced passageways 110 permitting passage the'rethrough of exhausting fluid medium from motor 31. a A tool mounting base plate 111 is provided with a channelway 112 connected to passageway 101 in housing 100 by means of a flexible hose .113.

I Engine 31 comprises a cylinder 32 fixedly connected to base plate 111 by means. of a threaded bushing or nipple 33 and bolts 34. Reciprocablyarranged in cylinder 32 is a piston 35 receiving fluid'medium under pressure from annular recess 36 in cylinder 32. Piston 35 is provided with a pair of spaced passageways '37 and 33 which alternately discharge exhausting fluid medium again'st opposite ends of thebore of cylinder 32 in a manner so that both piston 35 and cylinder 32reciprocate, the fluid medium under pressure exhausting through exhaust ports 39 in cylinder 32, thence through openings 110 in plate 109, and finally out to the atmosphere through the bore 130 in housing 100. It will be apparent thatcylinder'32, piston 35, and other associated elements the rnotor assembly are identical with corresponding elements of the forms of the invention illustrated in Figs. 1 and 5, for example, and have been assigned like identification numerals.

It will be further apparent that base plate 111 is substantially identical with base plate 21 and base plate 21a "in the invention illustrated in Fig. 5, and that said tool mounting plate 111 can readily serve to mount various tools or work performing elements similar to those disclosed in connection with said base plates 21 and 21a, as desired.

As in the forms of the invention earlier discussed, the

form thereof illustrated in Figs. 14 and includes a tool mounting base plate and a reciprocatory motor includlng a cylinder .fixedly mounted with respect to said base plate, such base plate and motor forming what may be termed a motor and base plate assembly. In the form of the invention illustrated in Figs. 14 and 15, this motor and base plate'assembly is connected at the lateral edge of cylinder 32 thereof to the handle means comprising housing 100 by means of a flexible casing .120,

which is advantageously of relatively thin rubber construction and which is afiixed to said lateral edges of dimension and is advantageously relatively thin in charac'ter. Said casing 120 functions generally in the same manner as casing 24 in the form of the invention illustrated in Fig. l, and casing 50 in the form of the invention illustrated in Fig.5 to vibrationally isolate housing from the reciprocating motor and base plate assembly when the latter generates high frequency reciprocatory vibrations. Although shown in Figs. 14 and 15 as being moulded or formed with flat Walls of substantially even thickness, itwill be apparent that casing 'can be of corrugated or other similar configuration along one or more axes offvibration, such as along the principal or longitudinal axis thereof like side walls 52 of casing 50 in Fig.6, as desired; a V g It is to be noted further that the upstanding wall portions provided by all of these forms of resilient connecting means serve to permit a substantial degree of vibrations of the motor assembly longitudinally, laterally, rotatively, and even vertically with respect'to the associated

handle housing

10 or 100, and thus effectively isolates the handle housing and the hand of the operator from such vibrations, even when substantial downward pressure is applied against the handle means to increase the working action of. the tool.

It will be evident that the vibrational isolation of the hand of the operator from the vibrations of the motor and base plate assembly characteristic of the present invention is achieved by connecting'a flexible means of the type here presented from the handle means either directly to the base plate or to the cylinder of the motor of the assembly. However, in practice it has been found preferable to connect such flexible means from the handle means directly to the base plate, as in the forms of the invention shown in Figs. 1 and 5, since such arrangement thereby provides a relatively longer ventical dimension of the flexible casing with a relatively lower and more compact overall vertical dimension of the mechanism. Further this form of the invention as a result of its relative compactness exhibits better guiding control and a comparatively greater degree of vibration isolation because the vibrations of the motor are in part absorbed by the tool action before being transmitted to the flexible casing.

Mode of operation Much of the mode of operation of the mechanisms of my invention herein is set forth above in connection With the description of the construction. of said devices.

With fluid operated reciprocatory sanders of common practice construction, so far as known to applicant, the eflectiveness of the device as respects sanding of the workobjectdepends, apart from the guiding function of the hand, solely upon the reaction against the hand of the operator to cause the device to have the necessary pressure for operation against the Work. 'That is, the force directed against the work requires in such device reaction of equal magnitude against the hand of the operator. Such construction involves the vibratory plate or base being rigidly connected to the vibratory reciprocating piston and the handle of the device being relatively fixed in at least one dimension of vibration with respect to the reciprocating mechanism. Therefore, a considerable degree of vibration is necessarily transmitted to the operator, and when the hand of the operator ceases to press the device against the work and the hand is removed from the device, such device will no longer operate as a sander but will go out'of control and jump about in non-sanding actiongover the work.

In contrast, *applicants device operates as V a sander, scraper, or like device, to the extent of the weight of the machine with the fluidpressure turned on and the hand of the operator removedguiding of the device over the work may even be done by pulling the device over the work with a cord or string. The device will not go out "of control in the sense that occursin the case ofsaid "c m p v i e structure referred to above. If greater sanding effect is desired, then greater weight may be added and the device may be manipulated by leading it by a cord. Thus, the hand of the operator, with my device, may be used to increase the pressure contact of the device upon the work as a weight. Thus, it will be apparent that the mode of operation of the device of the applicant is clearly different from that of the conventional structure defined.

The unanchored and freely reciprocating piston 35 is free to impart its impulses to the cylinder 32. It is unanchored and free to reciprocate because it is not directly connected to the vibratory or reciprocatory base plate 21. If it were so connected, i.e., integrally formed, then by pressing the device hard against the work (i.e., the piece being sanded or scraped or polished, etc.) the piston could be stalled if said mounting plate for the abrasive sheet (in case of the sander) is held still and immovable. But in the device of my invention, there is no such integral interconnection and the piston is free to respond to the fluid pressure.

Since many embodiments can evolve incorporating this inventive concept, and since many modifications can be made in the embodiments hereinbefore shown and described, it is to be understood that all matter herein is to be interpreted merely as illustrative and not in a limiting sense, and that such further modifications are to be construed as being within the scope of the present invention, as defined by the following claims.

This application is a continuation-in-part of my copending application Serial No. 301,313, filed July 28, 1952, now abandoned, entitled Reciprocating Mounting Means for Mounting Thereon a Sanding or Like Tool, which is in turn a continuation-in-part of my application Serial No. 97,663, filed June 7, 1949, entitled Sanding and Polishing Machine.

What is claimed is:

1. A manually manipulatable fluid pressure operated reciprocatory vibratory mechanism comprising a base plate, on which may be mounted a work engaging tool; a motor having a cylinder and a free floating piston therein said cylinder having only contact mounting on said. base plate; and a housing member extending over and independently of and forming no part of said motor and in spaced relation thereto mounted on said base plate, by a flexible means, an upper portion of said housing member functioning as a grasping member as a handle.

2. The mechanism of claim 1 further comprising the 10 flexible means of a form exhibiting three dimensional resiliency connecting said housing member to said base plate.

3. The mechanism of claim 1 further comprising the flexible means of a corrugated accordion-like acting longitudinal walls directly disposed on said base plate.

4. The mechanism of claim 1 further comprising a pressure fluid conduit extending from a source of pressure fluid to said housing member; a valve in said conduit controllable from said handle governing the admission of fluid pressure to said motor; and a conduit extending from said valve member to said cylinder of said motor, a portion of which conduit comprises a flexible member.

5. The mechanism of claim 1 further comprising a pressure fluid conduit extending from a source of pressure fluid to said housing member; a valve in said conduit controllable firom said handle governing the flow of fluid pressure, a portion of said conduit being of a flexible character and a portion extending through the base plate to said cylinder.

6. The structure of claim 1 further comprising a separating member separating the upper portion of said housing from said motor, said member having vents therethrough permitting the escape of exhaust air from the motor to pass therethrough; and sound deadening fibrous material positioned in said housing member above said separating member.

7. The mechanism of claim 4 further comprising whereby the free floating piston of said motor may continue to reciprocate even though the base plate is held stationary.

References Cited in the file of this patent UNITED STATES PATENTS 1,115,704 Manes Nov. 3, 1914 1,276,167 Brown Aug. 20, 1918 1,768,942 Szewczyk July 1, 1930 1,953,534 Everett Apr. 2, 1934 1,954,489 Partlow Apr. 10, 1934 2,221,448 Goodstein Nov. 12, 1940 2,245,545 Miller et a1. June 10, 1941 2,251,329 Ekstrom Aug. 5, 1941 2,272,008 Kehle Feb. 3, 1942 2,367,668 Champayne Jan. 23, 1945 2,393,592 Crosby Jan. 29, 1946 2,643,731 Schmidt Jan. 30, 1953 2,821,962 Swanson Feb. 4, 1958